1. Field of the Invention
The present invention relates to, in pharmaceutical and food fields, low-substituted hydroxypropylcellulose which is excellent in compressibility, flowability, disintegration and texture in oral cavity, and which is water-insoluble and swellable when it absorbs water; and a rapidly disintegrating solid preparation using it.
2. Description of the Related Art
High-quality preparations have recently been required in the pharmaceutical or food field. Particularly in the pharmaceutical field, the number of unstable drugs is increasing among newly developed drugs and additives usable for them have been limited from the standpoint of their interaction. Under such a situation, low-substituted hydroxypropylcellulose is a preferable additive because it has both excellent stability due to its non-ionic nature and compressibility. However, the low-substituted hydroxypropylcellulose conventionally put on the market contains much fibrous particles and therefore lacks flowability. Accordingly, it should be used in combination with another additive having good flowability when direct tableting is applied. In addition, an amount of low-substituted hydroxypropylcellulose to be added is also limited.
In Japanese Patent Application Unexamined Publication No. 2008-133432, proposed is low-substituted hydroxypropylcellulose having improved compressibility and flowability, which has widened its application range to direct tableting. However, the disintegration of the low-substituted hydroxypropylcellulose is equal to that of the conventional one so that a further improvement in the disintegration is required.
Japanese Patent Application Unexamined Publication No. 2000-103731 discloses a rapidly disintegrating solid preparation comprising a pharmaceutical component, a sugar, and low-substituted hydroxypropylcellulose having a hydroxypropoxyl content of 5% by weight or greater but less than 7% by weight. However, the low-substituted hydroxypropylcellulose described in Japanese Patent Application Unexamined Publication No. 2000-103731 is fibrous and inferior in flowability, and has deteriorated swellability, which sometimes increases the disintegration time.
There is therefore a demand for the development of an additive excellent in compressibility, flowability, disintegration and texture in oral cavity.